Edward h



(No Model.)

B. H. AMI-1T. BRUSH SHIFTER FOR DYNAMO ELECTRIC MACHINES. No. 340,539.

Patented Apr. 2'7, 1886.

'4V PiTERS. Pho'mblhogrzphar. Wnhingwn, D (L UNITED STATES PATENTOFFICE.

EDlNAR-D H. AMET, OF CHICAGO, ILLINOIS, ASSIGNOR TO H. A. STREETER, OFSAME PLACE.

BRUSH-SHIFTER FOR DYNAMO-ELECTRlC MACHINES.

SPECIFICATION forming part of Letters Patent No. 340,539, dated April27, 1886.

Application filed January 28, 1886. Serial No. 190,030. rNo model.)

To aZZ whom it may concern.-

Be it known that I, EDWARD H. AMET, a citizen of the United States,residing in Chicago, in the county of Cook and State of Illinois, haveinvented a new and useful Improvement in Brush-Shifters forDynamo-Electric Machines, of which the following is a specification.

My invention relates to certain improvements in brush-shifters of dynamo-machines for regulating the current generated.

' In my invention the position of the collect ing-brushes of thegenerator is automatically regulated or adjusted by means of acontrolling magnet included in the circuit to be regulated, whichoperates as a relay to open and close circuits in which twoelectro-magnets are included. One of these latter magnets operates totilt a rocking lever in one direction, and move aconstantly-driven gearor friction wheel into connection with a similar gear or friction wheelon the shaft which carries the pulley for shifting the brushes. Theother of these two magnets, when the circuit is closed through the same,operates to tilt the rocking lever in the opposite direction, and in asimilar manner give an opposite movement to the brushes of thegenerator. When the circuit through both these magnets is open, therocking lever stands in a horizontal or normal position, so that boththe gears on the rocking lever remain out of connection with the gear onthe shaft of the brush-shifting pulley.

My invention also consists in the novel de- Vices and combinations ofdevices herein shown and described, more particularly pointed out in theclaims.

In the accompanying drawings, which form a part of this specification,and in which similar letters of reference indicate like parts, Figure 1is a side elevation of a device embodying my invention, showing also adiagram of the circuit-connections. Fig. 2- is a plan view of therocking lever and its operating-magnets, and Fig. Sis a rear view of thesame; and Fig. 4 is a section of the frictionpulley, through which thepower is communi cated to the brush-ring.

In said drawings, A represents a dynamomachine, which may be of anysuitable or ordinary construction, A A its collectingbrushes, and A theexternal circuit, the current on which is to be regulated.

B represents a controlling or relay magnet included in the main circuitA, either directly or in a shunt or branch circuit, B, connectedtherewith. Vhere the device is used with an incandescent-lightmechanism, the magnet B should beincluded in a branch, 13; but where theapparatus is used on an arc-light mechan- 6o ism the magnet B should beconnected in series on the main circuit.

D and D are two electromagnets, which are normally open circnited, andwhich operate the tilting lever E in one direction or the other,according as the circuit is closed through magnet D or D. This tiltinglever E carries two constantly oppositely-driven friction-wheels, e 8.These friction-wheels e 6 may be constantly driven in opposite direc- 7of, which carries on one end a friction-wheel,

f, which engages one or the other frictionwheels, 6 e, according as thelever is tilted in one direction or the other. lVhen the lever E remainsin its normal or horizontal position neither of the friction-wheels e eengage the friction-wheel f. On the front end of the shaft fasprocketwheel or pulley, f, is provided, which communicates with thebrushes A A, or their rotary carrier, by means of a sprocket wheel,chain, or band, f sprocket-wheelf is preferably not keyed rigidly to theshaft f, but is connected thereto by means of a double friction ring orclamp, f, or other suitable friction device, so that the pulley orsprocket wheel f may give or 5 yield when necessary, and thus preventstrain upon the mechanism after the brushes reach the limit of theirmovement.

The relay-magnet'B is provided with a movable armature-switch lever, b,which operates to close the circuit through the magnet D or the magnetD, according as said switch is This driving-pulley may 75 The 0 broughtin contact with the contact-piece b or the contact-piece b. A spring, b,and its adjusting-screw b, serve to hold the switch b out of connectionwith both the contact-points b b" when the normal or proper amount ofcurrent is flowing through the circuit.

A wire, G, leads from the contact-piece b through the magnet D to thebinding-post N, which is connected to the main circuit by a wire, n, anda wire, H, leads from the contact- .piece b through the magnet Dto thebindingpost N;

In operation, when the current on thecircuit A is at its normal orproper amount the switch or armature-lever b of the relay-magnet willoccupy an intermediate position between the contactpoints I) and b, andthus both the magnets D and D will remain out of circuit. When for anycause the current on the circuit A exceeds its proper strength, therelay magnet B will move the switch 1; into connection with thecontact-piece b, and thus close the circuit G through the magnet D,thereby pulling that end of the rocking lever E down, so that itsconstantly-revolving friction-wheel e engages the friction-wheel f onthe pulley-shaft f, and causes said shaft and pulley to rotate in thedirection necessary to move the brushes A A to diminish the amount ofcurrent generated. This movement of the brushes A A will continue untilthe normal strength of the current is restored, when the armature of therelaymagnet will resume its normal or central position, and thus cut outthe magnet D, when the shaft f will of course cease rotating. YVhen, onthe other hand, the current falls below its normal or proper amount, therelay magnet B being thereby weakened,its armature b will be therebypulled into connection with the contact-point b by the spring b, thusclosing the circuit through the opposite magnet, D, and thereby causingthe shaftf and the brushes A A to rotate in the opposite-direction, andthus increase the amount of current generated until the normal or propercurrent strength is restored, when the relay B will again out out themagnet D. By this means, as power for shifting the brushes A A isfurnished by the constantly driven gears, and as the friction wheels orgears are moved in and out of contact by the magnetsD and D, which arenormally out of circuit or short-circuited, the controlling-magnet B hasno work to do, except to open and close the circuits through the magnetsD and D, and therefore the regulator is and can be readily madeextremely sensitive and quick to. respond to very slight changes in thecurrent, and consequently the current will be maintained prac ticallyand constantly at its proper amount.

My regulator mechanism is so delicate that it will respond to so slighta change as that without injury to the remaining lamps; and

gether with the requisite pressure.

incandescentlamps and are lamps may also be run on the same circuit.

My regulator is so delicate and sensitive that itwill readily respond toa very slight change in the current-as, for example, that of one-tenthof an ampere.

The constantly-driven gear e, which communicates motion to the gears e eon the tilting lever E, will have a tendency to tilt the lever,especially when one of the frictionwheels, 0 or e, is pressed againstthe frictionwheel f and the brushes are being shifted or moved; but thepull of each of the magnets D D is sufficient to overcome this opposingforce and hold the friction-wheels e or e and f to- This force operates,of course, in favor of one of the magnets and against the other-that is,it helps magnet D hold the friction-wheel e against the wheel f andopposes the magnet D. The magnet D might therefore be made slightlysmaller or weaker than the magnet D; but in practice I make both magnetsof the same size, as is shown in the drawings, as the disturbinginfluence of the gear a on the lever E is comparatively slight inrelation to the force of the magnets D D. When neither of the frictionse or e are pressed against the wheel f by the magnets D or D, thefriction of the loose gears e or e orthe resistance offered by them tothe gear e is so slight that the latter has such a very slight tendencyto pull the lever E that it is inappreciable, and whatever tendencythere may be is or may be balanced by the adjustment of the lever or ofthe armatures carried by it. It will of course be understood that thistendency of the gear a to tilt the lever E has no eifect whatever uponthe sensitiveness of the apparatus, as its sensitiveness dependsentirely upon the delicacy of adjustment of the relay-magnets B, whichopens and closes the circuit through the operating-magnets D and D. Theonly efl'ect of this tilting tendency of the gear 6 on the lever E is torequire the use of larger magnets D D than might otherwise be necessary.

I claim- 1. The combination, with a dynamo and its brushes, of arelay-magnet, B, magnets D and D, circuits through which are opened andclosed by said relay-magnet, rocking lever E, provided withconstantly-driven wheels 0 and 0, one on each side of its pivot, shaftf, furnished with wheel f, engaging with one or the other or" neither ofsaid wheels e and 6, according as said rocking lever is tilted in onedirection or the other or occupies its normal position, and a connectionbetween said shaft f and said brushes, substantially as specified.

2. The combination, with a dynamo and its brushes, of a relay-magnet, B,magnets D and D, circuits through which are opened and closed by saidrelay-magnet, rocking lever E, provided with constantly-driven wheels 6and 0, one on each side of its pivot, shaft f, furnished with wheel f,engaging with one or the other or neither of said wheels e and e, aa

cording as said locking lever is tilted in one direction or the other oroccupies its normal position, wheel f and chain or band f conneetingsaid wheel f and said brushes, substantially as specified.

3. The combination, with a dynamo and its brushes, of a relay-magnet, B,magnets D and D, circuits through which are opened and closed by saidrelay-magnet, rocking lever E, provided with constantly-driven wheelseand 6, one on each side of its pivot, shaft f, furnished with wheel fengaging with one or the other or neither of said wheels 6 and 0,according as said rocking lever is tilted in one direction or the otheror occupies its normal

